Combination valve and switch mechanism



Feb. 6, 1951 G. K. NEWELL 2,540,753

COMBINATION VALVE AND SWITCH MECHANISM Original Filed March 3, 1945 2Sheets-Sheet l 25 I i5L l Vern V0106 Mechanism I 26 Bra/Fe Cylinder f ii115 f O 27 fi I I I 11% J i 20 J Tooiher/ Sanding 106 o 0 28 end of CarReservoir 2i 108 a, 110 19 -&

Direezl'on of fraud INVENTOR. George KNewelZ ATTORNEY Feb. 6, 1951 G. K.NEWELL COMBINATION VALVE AND SWITCH MECHANISM Original Filed March 3,1945 2 Sheets-Sheet 2 5g "Q82 g 2 9 G 29 A; 4212i 28K 5 26 i i 55 i 42$156 AOa- 55 -45 Ed 16d l 77 88 l 1 86 87 7 79 I 80 i 62 1 a2 a5 a1 a5\J 84 98 92 100 9s v INVENTOR. 95 94 George K vewell A M97 QM 99 M01ATTORNEY Patented Feb. 6,

COMBENATION VALVE AND SWiTCH MECHANISM George K. Newell, Pitcairn, Pal,assigncr to The Westinghouse Air Brake Company, Wilmerding, Pa., acorporation of Pennsylvania Original application March 3; 1945;

Serial No;

580,907. Divided and'this application September 25, 1946, Serial No.699,192

4 Claims.

This invention relates to combination valve and switch mechanisms andhas particular relation to a combination valve and switch mechanism ofthe fluid pressure operated type, the present application being adivision of my prior pending application, now Patent No. 2,447,713.

While the combination valve and switch mechanism constituting my presentinvention is adapted for use in various situations, it is particularlydesigned and adapted for use in fluid pressure brake control systems forvehicles, such as railway cars and trains, to automatically control thebrake application and sanding of the rails in a manner to preventsliding of the vehicle wheels. In order to adequately describe thecharacter, operation, and use of the combination valve and switchmechanism constituting my present invention, it is described herein inconnection with a fluid pressure brake control apparatus of the typeincluding means for de tecting the slipping condition of a vehiclewheel.

As employed herein the term slipping or slipping condition and similarvariants refers to the rotation of the vehicle wheel at a speeddiffering from that corresponding to the speed of the vehicle at a giveninstant. As is well known, a slipping condition of a vehicle wheel maybe induced either by excessive propulsion torque, in which case thewheel rotates at a speed higher than that corresponding to vehiclespeed, or induced by excessive braking force, in which case the wheelrotates at a speed less than that corresponding to vehicle speed. In thepresent application the apparatus to be described relates to brakecontrol and the term slipping will therefore refer to rotation of thevehicle wheel at a speed less than that corresponding to vehicle speedunless otherwise indicated.

When the braking forces exerted on a vehicle wheel while the vehicle isin motion are such as to exceed or overcome the adhesion between theWheel and the rail or road surface on which the wheel rolls, the wheelinstantly begins to decelerate at an abnormally rapid rate toward a zerospeed or locked condition. If the wheel reduces in speed to the lockedor non-rotative condition, it is dragged along the rail or road surface.In the present application this is designated as a sliding condition.The tw terms slipping and sliding and their respective variants areaccordingly not synonymous in meaning and the distinction between theseterms must be borne in mind in reading the subsequent description of myinvention.

Sliding of railway car wheels has long been a problem which therailroads have sought to solve for the reason that sliding of car wheelsproduces flat spots on the wheels and tends to ,roads desire toeliminate.

lengthen the stopping distance of the train. Moreover repair andreplacement of the flat wheels is an item of maintenance which the rail-Numerous proposals and devices have been made and employed for detectingthe incipiency or imminence of a sliding condition of the wheels on thebasis of the abnormal rate of deceleration of a vehicle wheel while itis in a slipping condition prior to actually becoming locked andsliding. Such devices or apparatus have been of an electrical or amechanical nature and have functioned to rapidly reduce the degree ofapplication of the brakes on a slipping wheel sufficiently to insure therestoration of the wheel back to a speed corresponding to vehicle speed,without permitting vide apparatus for automatically reducing the degreeof the braking forces reapplied to a wheel that slips in order tominimize the possibility of recurrent or repeated slipping cycles. Suchdevices, while performing the objective of preventing recurrent slippingcycles, nevertheless provide a penalty in the way of reduced brakingforces resulting in possible lengthening of train stopping distance.

It is desirable, therefore, not only to protect the vehicle wheelsagainst sliding but also to provide for reapplication of the brakes onthe Wheels following any slipping condition of the wheels to a highdegree so that there is no substantial penalty in the way of lengtheningof stopping distance.

It has accordingly been proposed t provide apparatus for automaticallysanding the rails in advance of the car wheels, at the time a slippingcondition of any of the car wheels first occurs during any one brakeapplication, for the purpose of so increasing the adhesion between thewheels and the rails as to enable full reapplication of the brakes onthe wheels without causing recurrent slipping cycles on a wheel whichfirst slipped and without causing slipping of other wheels on the samecar of the train.

It is an object of my present invention to provide a novel combinationvalve and switch mech-- anism adapted to function to relieve the brakingforces associated with a slipping Wheel so as to prevent sliding of thewheel and to simultaneously effect or control the initiation of sandingof the track rails in advance of a group of car wheels including theslipping wheel.

The above object, and other objects of my invention which will be madeapparent hereinafter, are obtained by an embodiment of my inventionsubsequently to be described and shown in the accompanying drawingswherein Figure l is a simplified diagrammatic view, showing a fluidpressure brake and sanding control apparatus employing my novelcombination valve and switch mechanism, and

Figure 2 is an enlarged sectional View of my combination valve andswitch mechanism, showing complete details of construction thereof.

Description fully and adequately describe the character and function ofmy combination valve and switch mechanism, it is necessary to describean environment including a simplified type of fluid pressure brakecontrol apparatus of the well-known straight-air type in conjunctionwith the valve and switch mechanism itself.

Referring, therefore, to Figure l, the fluid pressure brake controlapparatus shown comprises a brake cylinder ll operative throughconventional brake levers and rigging, not shown, in response to thesupply of fluid under pressure thereto to effect application of thebrakes on the wheels of a wheel truck; a straight-air or control pipe i3is charged with fluid under pressure to a degree corresponding to thedegree of application of the brakes desired, as by suitable apparatusillustrated simply as a brake valve it of the well known self-lappingtype; a reservoir l5 normally charged with fluid at a certain uniformpressure by a fluid compressor (not shown) and my novel combinationvalve and switch mechanism, referred to as vent valve mechanism is,arranged to control the supply of fluid under pressure from the controlpipe it to the brake cylinder 5 l and the automatic release of fluidunder pressure from the brake cylinder ll under the control of socalledDecelostats or wheel-slip detecting devices ll of the rotary inertiatype, associated with the wheels l2.

The apparatus shown in Figure 1 further includes sanding and sandingcontrol apparatus comprising a plurality of sandin devices, hereinafterreferred to simply as sanders 18, of well known construction effectiveupon the supply of fluid under pressure thereto to deliver sand to therails immediately in advance of the vehicle Wheels l2, a sandingreservoir l9, and an electromagnetically operated control valve 28,hereinafter referred to simply as the sanding magnet valve, forcontrolling the supply of fluid under pressure to charge the sandingreservoir l9 and the supply of fluid under pressure from the sandingreservoir to the sanders it. A suitable electro-magnetically operatedcounting device 2! may also be provided for re istering the number ofoperations of the vent valve mechanism in response to the occurrence ofwheel slip conditions.

Considering the parts of the apparatus in In order to greater detail,self-lapping brake valve M is of the well-known type having aself-lapping valve mechanism including a rotary operating shaft to whichan operating handle ltd is attached. In the normal or brake releaseposition of the brake valve handle lie-la, the self-lapping valve Mvents fluid under pressure from the control pipe it through a branchpipe 53a and an exhaust port and pipe 22 at the brake valve. When thebrake valve handle l lo is shifted out of its brake release positioninto its application zone, the selflapping valve mechanism of the brakevalve IQ is operated to cause fluid under pressure to be supplied fromthe reservoir 55 by way of pipes 23 and 2s and pipe lilo to the controlpipe It, the pressure in the control pipe being automatically limited toa pressure dependent upon the degree of displacement of the brake valvehandle out of its brake release position into the application zone.

The control pipe It extends longitudinally of a car and is suitablyattached to the body of the car, sections of the control pipe onsuccessive cars being coupled through suitable hose couplings 25 inconventional manner to provide a so-called train pipe extendinthroughout the length of a train.

The brake cylinder l l and the vent valve mechanism iii are carried onthe spring-supported frame of the Wheel truck ll. Fluid under pres sureis supplied from the control pipe it to the brake cylinder by way of aflexible branch conduit or pipe 26, connecting the control pipe to thepipe bracket portion of the vent valve mechanism H3, and a pipe 2!connecting the pipe bracket portion of the vent valve mechanism iii tothe pressure chamber of the brake cylinder l l. Pipe 2i may be eitherrigid or flexible as desired. As will hereinafter appear, the vent valvemechanism it is normally conditioned to establish a communicationtherethrough between the branch pipe 25 and the brake cylinder pipe 21so that the brake cylinder ii is charged to the same pressure as thatestablished in the control pipe it. The several Deeelostats ii areconnected pneumatically to the pipe bracket portion of the vent valvemechanism it through a flexible conduit or pipe 28, having correspondingbranches 28a and 23b.

The vent valve mechanism 55 is identical, in part, to the vent valvemechanism disclosed and claimed in the oopending application of JosephC. McCune, now Patent No. 2,366,944, assigned to the assignee of thepresent application. According to my present invention, the vent valvemechanism shown in the patent of Joseph C. McCune just referred to ismodified in a manner to function as both a pneumatic or fluid pressurecontrol valve device and as an electrical switch device.

Referring to Figure 2, vent valve mechanism l6 comprises a pipe bracketand mounting section ltd, a valve or body section 56b, a cap sectionH30, and a switch casing section ltd. The casing sections lea, E62) andH30 are suitably secured together by screws, not shown, with sealinggaskets interposed between the cooperating contact faces of the casingsections. The switch casing section i602, which is in the form of atubular member or sleeve, is adapted to be supported from the casingsection 55b in the manner hereinafter to be described.

The pipe bracket section Illa has three ports or passages 263:, Elm and2am therein to which correspondingly numbered pipes or conduits 26, 21,

and 28, respectively are, connected. ;A port-29 in the body of the pipebracket section connects the passage 26a: and the passage 28a: and isthreaded to receive a screw type choke fitting 36 having arestricted'orifice 3|. The end opening of passage 26x at the inner faceof the pipe bracket section |a is opposite the port 29 so that chokefitting 30 may be inserted in the port through the end of the passage231: before attachment thereof to casing section lBb. The purpose of thechoke fitting 36 will be explained presently.

The valve section |6b has a lower conical portion in which a large ventport 32 is provided which is controlled by a differential piston valve33.

The differential piston valve 33 comprises an annular piston 34 and adisc type piston 35 of smaller diameter, the two pistons being connectedby a tubular stem 36. Theouter face of the piston 35 has an annulargasket 37 secured therein for engaging an annular rib seat formed on aseat bushing 38 fixed, as by a press fit in a circular bore of thecasing section lob constituting vent port 32.

The piston 34 operates in a bushing 39 fixed as by a press fit in a boreformed in the casing section lfib. The piston 35 operates in a similarbushing 40 of smaller diameter also fixed as by a press fit in a boreformed in the casing, in coaxial relation to the bushing 39.

The bushing 40 extends through a chamber 4| having a port 4011 to whichthe passage 21$ in the pipe bracket section |6a is connected. Theinterior of the bushing 40 opens at the upper end thereof into a chamber42 having a port 42a to which the passage 26:10 in the pipe bracketsection Hia. is connected.

A plurality of peripherally spaced ports 43 in the bushing 40 providescommunication between the chamber 42 and the chamber 4| when the piston35 of the piston valve 33 is seated on the seat bushing 38. It will thusbe apparent that when the control pipe l3 in Figure 1 is charged withfluid under pressure, such fluid under pressure flows through the pipe26, passage 2600 and port 42a to chamber 42, where it acts on the lowerface of the annular piston 34, and thence through the ports 43 in thebushing 40 to the chamber 4|, and through the port 40a, passage 1x andpipe 21 to the brake cylinder ll.

Formed above the annular piston 34 within the bushing 39 is a chamber. Apassage 28a formed in the cap section |6c connects chamber 44 to apassage 28y in the casing section lfib that, in turn, is connected tothe passage 28:0 in the pipe bracket section We. It will thus be seenthat when fluid under pressure is supplied to the chamber 42 beneath theannular piston 34, fluid under pressure is simultaneously suppliedthrough the orifice 3| in the choke fitting 30 from the passage 26a: tothe passage 28a:, and thence through the passages 28y and 28a to thechamber 44 above the piston 34.

A coil spring 45, contained in the tubular stem 35, is interposedbetween the face of the can section I60 and the inner face of the piston35 for urging the piston 35 into seated position on the seat bushing 38in opposition to the force of the fluid pressure in chamber, ,42exertedupwardly on the lower face of the piston 34.

When fluid under pressure is vented from the pipe 28, as by operation ofthe one or more of the Decelostats l! in the manner hereinafter to bedescribed, ata rapid rate Iasterthanthat at which fluid under pressureis supplied through the choke orifice 3| to the passage 2390, adifferential fluid pressure is built up on the annular piston 34effective to urge the piston 34 upwardly in opposition to the force ofthe spring 45, the piston ultimately seating on the contact face of thecap section lfic within the chamber 44.

In such position of the piston valve 33, the piston 35 is in a positionabove the ports 43 in the bushing 46, thereby cutting olf communicationbetween the chamber 42 and the chamber 4| through which fluid underpressure may be supplied from the control pipe l8 to the brake cylinderAt the same time, with the piston 35 unseated from the seat bushing 38,the chamber 4| and the connected brake cylinder H are connected toatmosphere through the ports 43 and the exhaust port 32 in the mannermore fully described hereinafter so that fluid under pres sure is thusrapidly exhausted from the brake cylinder I.

In order to maintain the piston valve 33 in its uppermost position, inwhich fluid under pressure is vented from the brake cylinder until thepressure in the brake cylinder reduces below a certain low pressure,such as eight pounds per square inch, the vent valve mechanism H3 isprovided with an arrangement comprising a poppet valve 46 and a controlvalve 41. The poppet valve '43 seats on a seat bushing 43 fixed in abore 43 in the cap section H50 and has a cylindrical guiding stem 5|]that is slidably received in a bore 5| in a screw plug 52 closing theopen end of the bore 49-. A coil spring 53, interposed between the screwplug 52 and the valve 46, yieldingly biases the valve into seatedposition on the seat bushing 48.

Extending from the valve 46 on the side oppo- Site the guide stem 50 isa, fluted stem 54 that operates slidably in the bushing 48 and has acircular end portion or extension that extends downwardly through thechamber 44 into the interior of the tubular stem 36 of the diiferentialpiston valve 33 in coaxial relation thereto. The lower end of the stem54 extends into sufficient proximity to a boss 55 on the inner face ofthe piston 35 that when the piston 35 is raised to its uppermostposition, the boss 55 engages the end of the stem 54 and unseats thevalve 46 a certain amount.

The control valve 41 is contained in a chamber '56 that is connectedthrough a passage 5! to the bore 49. If desired, a choke fitting 58having a restricted orifice 55 may be disposed in the passage 51, asshown, for somewhat restricting the rate of flow of fluid under pressurethrough the passage under circumstances hereinafter described. The valve41 is normally seated downwardly on a seat bushing 53, as by a spring65, in opposition to a spring 62 which tends to unseat the valve. Thespring acts on the closed end of a sleeve type follower 63 that operatesslidably in a bore 64 formed in a relatively large cap screw or screwplug '55 that is, in turn, screwed. into a suitably threaded bore in thecasing sec-- tion I60, the follower engaging the upper face of animperforate flexible diaphragm 3B of rubber or metallic compositionsecured in the casing section 60, as by clamping the periphery thereofby the screw plug 65. A protective washer 61' may be interposed betweenthe end of the screw plug 65 and the diaphragm 66 to prevent damage tothe diaphragm in response to the tortional 41 is thus subject by thepiston valve i clamping action-of the screw tightened home.

Surrounding'the bore M and the follower-63 in the plug 65 is an annularchamber 68 which is open to the upper face of thediaphragm 66. Chamber68 is also open to atmosphere through a passage 69 leading to anatmospheric port in. Port Hi also connects the chamber at the back ofthe sleeve follower 63 to atmosphere to prevent dash-pot action thereofinterfering with rapid unseating of valve ll.

Control valve t: controls communication between chamber 56 and a passage12 leading to the chamber ll. The inner seated area of valve to thefluid pressure in the chamber ii and the connected brake cylinder I I.

When the poppet valve lid is unseated upwardly 33, it causes the chamber44 to be connected through the bore 59 and passage 51, including thechoke orifice 59, to the chamber 56 at the lower side of the diaphragm66. Assuming sufficient fluid pressure to be established in the brakecylinder H, as hereinafter described, the valve M will have beenunseated by the brake cylinder pressure acting on the inner seated areathereof in opposition to the force of the spring 6%. With the chamber 55thus charged with fluid at the same pressure as that in the brakecylinder, the force of the spring plug 65 when it is bushing Bil.unseated simul aneously, the chambe 44 and the connected chamber 56 areconnected past the unseated valve the chamber 4 l. The pressure of thefluid in the chamber 44 thus reduces substantially in accordance withthe reduction of the pressure in the chamber ii and the connected brakecylinder H.

The piston valve 33 is maintained in its uppermost position by thepressure of the fluid in the chamber 42 beneath the piston 34 as long asthe control valve 41 is unseated. When the fluid pressure in the chamber56, active on the lower face of the diaphragm 66 and corresponding tobrake cylinder pressure, reduces to a low value such as eighteen poundsper square inch, the force exerted by the spring 6! becomes effective toreseat the valve ll. With the valve 4'! reseated, the fluid underpressure supplied through the orifice 3! of the choke fitting 33 fromthe supply pipe 26 and connected passage 26m and through the passages28x, 22y and 282 to the chamber 4:! above the piston 3, promptlyrestores the fluid pressure in value which, with the assisting force ofthe spring 45, is effective to promptly shift the piston valve 33downwardly to the position wherein the piston 35 is again seated on theseat bushing 38. A certain time interval elapses between the instantthat the valve ll is reseated and the instant that the piston 35 cutsoff the further venting of fluid under pressure from the brake cylinderi due to the time required to build u the pressure in the chamber 44through the choke orifice 3! sufficiently to shift the piston valve 33downwardly. During this time interval, the reduction of brake cylinderpressure continues, and at the time the piston 35 actually seats on theseat bushing 38 to out off further reduction in brake cylinder pressure,the brake cylinder pressure will have reduced to a value such as eightpounds per square inch.

With the piston valve 33 restored to its nortl and through passage 12 tothe chamber M to a mal position as just described, the .spring53 acts toreseat the poppet valve 46 by reason of the disengagement of the boss 55on the piston 35 from the end-ofthe stemtS of the .valve Mi. Spring 53is of such strength. as to maintain the valve 46 seated in opposition tothe pressure of the fluid pressure built up in the chamber 3 1 andacting onthe inner seated area of the valve as.

With the piston valve 33 restored to its normal position shown in Figure2, the supply communication between the supply pipe 26 and the brakecylinder pipe 2 is again established throu h the ports 43, and thepressure in the. brake cylinder-is thus again built up in accordancewith the pressure established in the control pipe [3.

Uponrestoration of fiuidpressure in the brake cylinder H, the valve 41is again unseated in response to the brake cylinder pressure activethrough the passage 12.011 the inner seated area of the valve.Chamberl'lfi is thus again charged to a pressure corresponding to brakecylinder pressure and such pressure acts through the passage 51 and bore49 on the outer face of the poppet valve 46 to assist spring 53 inmaintaining it seated against the pressure of the fluid in the chamber44.

It will thus be seen that when the pressure of the fluid in the chamberid is suddenly reduced by operation of one or more of the Decelostats Hin the manner more fully described hereinafter, the pressure of thefluid in the brake cylinder is promptly and automatically first reducedto a predetermined low pressure and then restored to a pressurecorresponding to that established in the control pipe i3.

According to my present invention, the vent valve mechanism It furtherincludes a switch mechanism within the switch casing section 55darranged to be operated in response to movement of the piston valve 33.To this end, a tubular switch support member 14 is provided having atits upper end a portion of reduced diameter provided with threadswhereby the member M may be screwed into the threaded end of the ventport 32 in the casing section I61) in such a manner that the fluid underpressure vented past the valve 35 from brake cylinde flows into thehollow interior of the tubular member "M.

As will be explained presently, the switch casll'lg section ltd issupported in concentric surrounding relation to the tubular member M. Inorder, therefore, to permit the escape of fluid under pressure frombrake cylinder i past valve 35 to atmosphere the tubular member M isprovided with a plurality of relatively large ports 15 in the wallthereof and the casing section Hill has a plurality of vent ports 16 inspaced relation around the periphery thereof, preferably at the lowerend thereof as shown.

The lower end of the tubular member M has a bore therein of slightlylarger diameter than the bore immediately adjacent thereto, so as toform an annular shoulder Ti serving as a stop for a cylindrical member18 of insulating material that is inserted endwise into the bore fromthe lower end of the tubular member i l. Embedded in the member 78 indiametrically disposed relation are two terminal posts 19 and 8%!respectively, which project radially outwardly through suitable openingsin the wall. of the tubular member H5. Insulating washers 8! surroundingthe terminal posts 19 and 80 may be provided in the openings in thetubular member 14 through which the terminal posts extend in order toinsure insulation of the terminal posts from the wall of the tubularmember. The terminal posts 79 and 80 are provided with tapp bores toreceive screws 82 for securing wires thereto.

At the lower end of the insulating member 78 is an annular recess forreceiving two arcuate contact segments or members 83 and 84 of suitablemetal or metallic alloy. The arcuate contact segment 83 is secured inplace by a screw 85 that engages in a tapped bore 86 in the terminalpost 19, thereby electricall connecting the segment 83 to the terminalpost 79. Similarly, the arcuate contact segment 84 is secured in placeby a screw 85 that engages in a tapped bore 81 in the terminal post 80,thereby electrically connecting the segment 84 to the post 80.

The cylindrical member E8 is provided with a central bore 88 in coaxialrelation to the tubular member 14 through which a metallic operatingstem 89 extends. term 89 is secured at its upper end, as by a screwthreaded connection, to a central point in the piston 35. The lower endof the stem 89 is provided with an insulating tip 98 having a screwthreaded connection with the metallic portion of the stem.

The insulating tip 98 of the stem 89 is adapted to engage a metallicsphere or ball contact 9| that is contained in a cylindrical bore 92 ofa cylindrical insulating member 93 secured in the bore at the lower endof the tubular member 14 immediately beneath and'in contact with themember 78. A coil spring 94 is interposed between the ball 9| and theclosed end of the insulating member 93 for urging the ball 9| upwardlytoward the arcuate contact segments 83 and 84. The length of the stem 89is such that when the piston 35 is seated on the valve seat 38, the ball9| is shifted downwardly from the contact se ments 83 and 84 tointerrupt the electrical connection therebetween. When the valve piston33 is shifted upwardly in the manner previously described, the upwardretraction of the stem 89 permits the ball 9| to be shifted upwardly bythe spring 94 into simultaneous brid ing contact with the arcuatecontact segments 83 and 84, thereby electrically connecting the twoterminal posts 19 and 80. For good electrical contact of the ball 9|therewith, the inner circular contact edges of the contact segments 83and 84 are shaped to conform to the curvature of the surface of theball.

In view of the characteristic operation of the piston valve 33 insnap-action fashion, it will be seen that the make and break ofconnections between the arcuate contact segments 83 and 84 by the ballcontact 9! will correspondingly have a snap-action characteristic. Theinsulatin tip 90 on the operating stem 89 prevents possible grounding ofthe circuit through the casing of the vent mechanism It, which groundinis undesirable.

The insulating members 18 and 93 are held in position by a threadedsleeve 95 that is screwed into the outer threaded end of the bore at thelower portion of the tubular member 74, the inner end of the sleeve 95engaging an annular shoulder formed on the member 93.

The switch casing section I 801 rests at its lower end on an annularmember or washer 96 that is fitted over the projecting threaded endportion of the sleeve 95 and is secured in clamped relation against thelower end of the tubular member 74 by an internally threaded cap member91 screwed over the outer threaded end portion of the sleeve 95. Inorder to insure the concentric relation of the casing section ltd withrespect to the tubular member 14, a plurality of peripherally spacednibs 98 are provided on the washer 96. These nibs are formed as bymaking two closely spaced radial cuts inwardly from the outer peripheryof the washer 96, the portion of the washer between the two outs beingbent upwardly to form the centering nibs 98. As will be evident in Fig.2 the nibs 98 are circularly arranged and thereby hold the lower end ofthe casing section Hid in a fixed position on the washer 96.

In order to prevent loosening and possible loss of the cap member 91, acotter pin 99 that extends through the cap member 97 and the sleeve 95,may be provided as shown.

The upper end of the casing section ltd is flared outwardly and engagesthe conical outer surface at the bottom of the casing section l6?) inclose contact so as to prevent the entrance of dirt or dust into theinterior of the casing section l6d.

Although not shown, an annular sealing gas-- ket of conical contour maybe interposed between the flared upper end of the casing section lid andthe conical portion of the casing section lfib to insure a tight seal ofthe casing section lSd against the casing section i612.

In order to enable at least a. portion of the fluid under pressurevented past the piston valve 35 to function in a manner to as ist inextinguishing the are drawn between the ball contact 9| and the contactsegments 88 and 84 as well as to clean the arcuate contact segments 83and 84 and the ball contact 3| of any dirt or dust that may possiblyaccumulate thereon, fluid under pressure is allowed to escape toatmosphere successively through the bore 88 in the insulating member 78,a port I 88 in the insulating member 93 at the lower end of the bore 92,and a port l0! in the cap member 97. The fluid under pressure escapingpast the ball contact 9! also causes rotation thereof, thus causindififerent portions of the ball to engage the contact segments 83 and 84when engagement of the ball and segments is effected and therebydistributing the wear uniformly to all portions of the surface of theball contact.

The Decelostats I7 associated with the vehicle wheels l2 are of the typedisclosed and claimed in the copending sole application of Joseph C.McCune, now Patent No. 2,447,709, and the copending joint application ofJoseph C. McCune and George K. Newell, the present applicant, now PatentNo. 2,447,710, both of which patents are assigned to the assignee ofthis application.

Since reference may be had to the patents just referred to for detailsof construction of the Decelostats it is deemed unnecessary to give morethan a brief description thereof in this application.

Essentially each of the Decelostats ll comprises a fly-wheel or rotaryinertia element suitably journaled for rotation in a casing attachableto the end of the axle journal of a railway car truck in place of theusual end cover, and a driving connection between the fly-wheel and theend of the axle so arranged that whenever a certain rate of decelerationor acceleration of the wheels l2 affixed to the axle occurs, as when thewheels slip, the corresponding rotational lead or lag of the flywheelwith respect to the axle is effective to cause unseating or a normalseated or closed pilot valve device Ha carried by the casingor aremovable part of the casing attached to'the axle journal. I

The branches 28a and 28b of the conduit or pipe 28 connected to the pipebracket portion of the vent valve mechanism It are connectedrespectively to corresponding pilot valve devices lid of diiierent wheeland axle units. Thus, when either of the pilot valve devices Ila areunseated or opened in response to the occurrence of aslipping conditionof the corresponding wheel and axle unit, fluid under pressure israpidly vented past the pilot valve devices from the pipe 23 and theconnected chamber M of the vent valve mechanism I6, thereby causing arapid reduction of the pressure in chamber i l and consequent operationthereof in the manner previously described.

The sanders l8 are of standard and well-known construction and adetailed description thereof is thus deemed unnecessary in the presentapplication. Sufllce it to say, each one of the sanders I8 includes ahopper I8a containing sand which is delivered through a delivery :pipeI83 to a point in advance of the corresponding vehicle wheel I2 inresponse to the supply of fluid under pressure to the correspondingsander.

Only two sanders are shown in Figure 1, one for each of the two vehiclewheels i2 shown. It will be understood, however, that an additionalsander is provided for each wheel of the wheel truck and fluid underpressure is supplied tooperate such sanders under this control of thecommon sanding magnet valve 20, as will be explained more fullypresently.

Fluid under pressure is supplied to operate the sanders l8 under thecontrol of the sanding magnet valve 29 which is, in turn, under thecontrol of the switch portion of the vent valve mechanism I6.

The sanding magnet valve 20 is of standard construction comprisingessentially a valve I04 that is normally biased to an upper seatedposition as by a spring I85 and is actuated to a lower seated positionin response to energization of a magnet winding or solenoid H35. Withthe magnet winding IE6 deenergized and the valve Hi l in its upperseated position, communication is established past the valve Hi l fromthe reservoir pipe 24 to the sanding reservoir I9, thereby causing thesanding reservoir to be charged with fluid at a pressure correspondingto that in the reservoir I5.

When the magnet winding M16 is energized and valve I04 is shifted to itslower seated position,

the supply communication to the sanding reservoir is cut off andcommunication is established from the sanding reservoir I9 to a deliverypipe I01. Delivery pipe I91 is connected by two branch pipes I08 to apipe I69 connected to both of the sanders I8 for the wheels I2 on oneside of the car truck and to a pipe Hi] connected to the sanders, notshown, for wheels on the other side of the car truck.

It will thus be apparent that when the magnet winding I06 of the sandingmagnet valve 2:! is energized, fluid under pressure is supplied from thesanding reservoir I9 to all of the sanders I8 for all wheels of theparticular wheel truck.

The manner of energizing the magnet winding I06 of the sanding magnetvalve under the control of the switch portion of the vent valvemechanism It will be apparent in Figure -1. Briefly, pair of bus wiresHi and M2 are provided which are connected respectively to the fitpositive and negative terminals of a source of direct current; such asthe usual storage battery H3 provided on passenger cars. The magnetwinding I of the sanding magnet valve 28' is connected in seriesrelation with the switch portion of the vent valve mechanism Iii acrossthe battery bus wires Ill and H2. It will thus be seen when the pistonvalve 33 is actuated upwardly in response to the reduction of thepressure in the chamber i l by operation of one or more of the pilotvalve devices l'la of the Decelostats ll, the switch portion of the ventvalve mechanism is thereby operated to close the circuit for energizingthe magnet winding Hi5.

It is desirable for purposes of test and scientiiic analysis to know thenumber of times that the vent valve mechanism It is operated over agiven period of time or over a given travel distance of a train. Forthis purpose, the counting device 2!, of standard and well-knownconstruction, is connected in parallel relation to the magnet windingN36 to the sanding magnet valve 2t. Thus, each time that the pistonvalve 33 is operated through a cycle, that is raised and lowered, theelectro-responsive portion of the counter 25 is energized anddeenergized successively, the register of the counter advancing one unitwith each individual energization of the electroresponsive portion ofthe counter.

Operation The operation of the apparatus disclosed in Figures 1 and 2should be apparent from the previous description. However, a briefsummarization thereof may be helpful for further understanding of theoperation as a whole. Let it be supposed that train of cars equippedwith the brake and sanding control apparatus shown in Figures 1 and 2 istraveling under power and that it is desired to effect an application ofthe brakes. The engineer on the locomotive of the train accordingly cutsoff the propulsion power in the usual manner and causes the control pipeI3 to be charged with fluid under pressure corresponding to the desireddegree of application of the brakes, as by operation of the brake valveI4. Fluid under pressure is accordingly supplied to the brake cylinderII in the manner previously described and application of the brakesassociated with the vehicle wheels 92 is accordingly effected.

As long as the wheels continue to roll in the normal fashion anddecelerate at a rate corresponding to the rate of retardation of thetrain, no further variation of the pressure in the brake cylinder iioccurs except in response to variation of the pressure in the controlpipe 53 under the control of the engineer, who may either increase crdecrease the pressure, as desired, to correspondingly increase ordecrease the degree of application of the brakes on the vehicle wheels.

If, when the brakes are first applied or at any time during a brakeapplication, a wheel unit of a particular car truck, taken as that shownin Figure 1, begins to slip due to excessive braking force in relationto the adhesion between the wheels and the rails, the pilot valve devicelid of the corresponding Decelostat will operate so as to causeoperation of the vent valve mechanism It to cut oil the supply of fluidunder pressure from the control pipe I3 to the brake cylinder of thecorresponding wheel truck and to vent fluid under pressure therefrom atrapid rate.

As previously described, the operation of the switch portion of ventvalve mechanism I6 incidental to and simultaneous with the operation ofthe vent valve mechanism to vent fluid under pressure from the brakecylinder I I causes energization of the magnet winding I66 of thesanding magnet valve 29 and of the operation counter 2 i. Fluid underpressure is accordingly supplied from the sanding reservoir IE) to thesandare 58 under the control of the magnet valve 28, thereby causing thesanders to operate to deliver sand in advance of the vehicle wheels [2of the wheel truck having the slipping wheel or wheel unit at the sametime that fluid under pressure is being vented from the brake cylinder.7

As previously described, the vent valve mechanism I5 is so constructedand designed that, once it is operated to vent fluid under pressure fromthe brake cylinder associated therewith, it remains conditioned tocontinue the reduction of pressure in the brake cylinder to a certainlow pressure such as eight pounds per square inch, after which it isautomatically restored to its normal condition wherein the furtherreduction of pressure in the brake cylinder is terminated and thecommunication through which fluid under pressure is supplied from thecontrol pipe to the brake cylinder is reestablished.

The time required for the pressure in'the brake cylinder to reduce toeight pounds per square inch from the pressure usually established inthebrake cylinder will ordinarily be of such length that the slippingwheels will have previously been restored to a speed corresponding totrain speed and be again decelerating in accordance with the rate ofretardation of the train by the time that the vent valve mechanism I 6is restored to its normal condition. Thus, when the vent valve mechanismIt is restored to its normal condition, the pilot "valve device I'Ia. ofthe Decelostat associated with the wheels which just slipped will havebeen reseated so as to terminate the exhaust o-f fluid under pressurefrom the pipe 23 and the chamber of the vent valve mechanism I6. Fluidunder pressure correponding to that established in the control pipe I3will thus be restored in the brake cylinder II so that the brakes on thewheel truck having the slipping wheel unit or Wheels willagain bereapplied in accordance with the pressure of the fluid in the controlpipe I 3.

If the so-called bad rail condition or condition of poor adhesionbetween the wheels and the rails is a continuing one, it is likely thatthe reapplication of the brakes on the wheels of the truck having thewheels which just slipped will again cause those wheels to begin to slipunless the adhesion between the wheels and the rails is improved in theinterim.

In this embodiment of my invention, the sanding of the rails isdiscontinued automatically iii response to the restoration of the ventvalve mechanism !6 to its normal condition by reason of thedeenergization of the magnet winding I06 of the sanding magnet valve 20in response to the restoration of the switch portion of the vent valvemechanism to its open position. In this embodiment of my invention,therefore, sanding of the rails is eifected substantially only duringthe time interval during which actual slipping of the wheels occurs. Theadvantage of the rail sanding in this embodiment of my invention lies inthe fact that the adhesion between the wheels and the rails is greatlyimproved by sanding during the slipping cycle of the wheels, therebytending to insure prompt restoration of the slip- 14 ping, wheels to aspeed corresponding to vehicle speed.

If following automatic restoration of fluid pressure in the brakecylinder II, the same or other wheels on which the brakes are applied bythe brake cylinder begins to slip, the above oper ation is repeated.

After a train is brought to a stop in response to an application of thebrakes in the manner pre-- viously described, the brakes associated withthe wheels continue to remain applied so long as a control pressureremains in the control pipe I3. This is so because the vent valvemechanism I6 is always restored to its normal condition automaticallyfollowing operation thereof under the control of the Decelostat pilotvalve devices I'Ia. In order to release the brakes prior to againstarting the train, the engineer reduces the pressure in the controlpipe I3 to atmospheric pressure, as by operation of the brake valve I4.Fluid under pressure is accordingly released from the brake cylinder IIby reverse flow from the brake cylinder to the control pipe and thenceto atmosphere through the exhaust port 22 at the brake valve.

The deenergization of the magnet winding I06 of a sanding magnet valve20 in response to each restoration of the vent valve mechanism I6 to itsnormal condition automatically causes recharging of the sandingreservoir i9, thus providing a constantly available source of fluidunder pressure for operating the sanders I8.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. The combination with a fluid pressure receiving device, of a combinedvalve and switch mechanism comprising a casing having a supply port, adelivery port, and an exhaust port, a valve element having one positionin which it establishes a connection between the supply and deliveryports through which fluid under pressure may be supplied to thereceiving device and operative to a difierent position in which itsevere the connection between said supply and delivery ports and opens aconnection between said delivery port and said exhaust port throughwhich fluid under pressure is released from the receiving device, a pairof insulated contact members in spaced relation to each other, a contactbridging element, resilient means constantly urging said bridgingelement toward a position in bridging contact with said insulatedcontact members, and a rigid element connected to the valve element andengaging said contact bridging element to separate it from the insulatedcontact members While the valve element is in its said one position andshifted in response to operation of the valve element to its diiferentposition to permit the said contact bridging element to engage thespaced contact members in bridging contact.

2. The combination with a fluid pressure receiving device, of a combinedvalve and switch mechanism comprising a. casing having a port therein, avalve eiement contained in said casing and normally positioned to closesaid port and establish a communication through which fluid underpressure may be supplied to the receiving device and operative to adifierent position closing said supply communication to the receivingdevice and opening a communication through which fluid under pressure isreleased through said port from said receiving device, a tubular membersecured in said port, an insulating support carried by and within saidtubular support, and having a passage therethrough in substantialcoaxial relation to the valve element, a pair of spaced contact memberssupported by said insulating member on opposite sides of said passagerespectively, a stem secured to the valve element and extendingcoaxially through said tubular member and the "p ssage in saidinsulating member, a contact bridging element contained in saidinsulating member, and resilient means biasing said contact bridgingelement toward a position in bridging contact with said contact members,contact bridging element being engaged by said stem whiie the valveelement is in position closing said port for cisengaging' the contactbridging element from said contact members and being moved in responseto operation of the valve element to its difierent position to permitthe engagement of the contact bridging element with the contact members3. The combination with a fluid pressure receiving device, of a combinedvalve and switch mechanism comprising a casing having a port therein, avalve cement contained in said casing and normally positioned to closesaid port and establish a communication through which fluid underpressure may be supplied to the receiving device and operative to adiiierent posi tion closing said supply communication to the receivingdevice and opening a communication through which fluid under pressure isreleased through said port from said receiving device, a tubular membersecured in said port, an insulating support carried by and within saidtubular support and havin a passage therethrc-ugh in substantial coaxialrelation to the valve element, a pair of spaced contact memberssupported by said insulating member on opposite sides of said passage*espectively, a stem secured to the valve element extending coaxiallythrough said tubular member and the passage in said insulating member, acontact bridging element contained in said insulatir member, resilientmeans biasing said contact bridging element toward a position inbridging contact with said contact members, said contact bridgingelement being engaged by said stem while the valve element is in itsposition closing said port for disengaging the contact bridging elementfrom said contact members and being moved in response to opera- NumberName Date 1,938,327 Green Dec. 5, 1933 2,222,542 Robison NOV. 19, 19402,310,261 Schwarzhaupt et a1. Feb. 9, 1943 2,356,177 Pierson Aug. 22,1944 tion of the valve element to its diiierent position to'permit theengagement of the Contact bridging element with the contact members, andmeans providing communication through which fluid under pressurereleased through said port from the said receiving device into tubularmember escapes to atmosphere.

4. The combination with a fluid pressure receiving device, of a combinedvalve and switch mechanism comprising a valve element having oneposition in which it establishes a supply communication through whichfluid under pressure may be supplied to the receiving device andoperative to a difierent position in which the supply communication isclosed and a diiierent communication is established through which fluidunder pressure is released from the receiving de-- vice, a pair ofinsulated contact members in spaced relation to each other, a contactbridging element, resilient means constantly urging said bridgingelement toward a position in bridging contact with said insulatedcontact members, a rigid element connected to the valve el ment andengaging'said contact bridging element to separate it from the insulatedcontact members while the valve element is in its said one position andshifted in response to operation or the valve element to its differentposition to permit the said contact bridging element to engage thespaced contact members in bridging contact, and means for causing fluidunder pressure released from the receiving device to flow past saidcontact members and said contact bridging element to effect the removalof dust and dirt particles that may collect thereon as Well as to assistin eX-- ting'uishing the are drawn between the contact bridging elementand said contact members;

GEORGE K. NENELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

